UK-POLOS.NET - THE VW Polo Forum

My polo is throwing up the engine management light every time I go out in it, I can switch the light off without any problems thanks to the scangauge but I think its about time to replace them.

The main code that comes up is the front sensor with the occasional code popping up telling me it's both.

I plan to change just the front one for now but not sure what brand to get, I have been told that NGK are the best but there are a load more companies that make them (Bosch, intapart, etc)

Has anyone on here changed theirs before, and if so what brand did you get ?

The codes I have been getting on the scangauge are:

P0141

P0142

I am presuming the P0141 is pre-cat and the P0142 is the sensor on the cat, can anyone confirm that please?

Before you do anything, check the wiring for the engine side lambda sensor

This commonly breaks down, and causes huge problems for alot of owners and faults that cant be explained

Its the wiring plug on the front of the gearbox where it normally fails.

As Alex says, I went to change my pre cat lambda and found the wiring on the car side of the harness was broken. I had to solder 4 out of the 6 wires. I've replaced my pre cat with a Bosch unit btw, I'm pretty sure my post cat was Bosch too but that was about 3 years ago now. £81 from GSF. I use Ross-tech for fault codes identification.

P0141 is a heater fail. That could very likely be the wiring mate!

Thanks for the replies, what's the easiest way to check the wiring other than visually ?

I could only see the break in the wires from underneath with the under tray off. It was right in the back of the multiplug.

Replaced both sensors now and all seems to be good again

Happy days, if only mine was that simple, 3 hours of cutting and soldering to fix it!

6n2stan wrote:Happy days, if only mine was that simple, 3 hours of cutting and soldering to fix it!

Is it just me or does lamba wires seem a git to solder

They are silicon coated gold plated wires. Not the easiest to solder.

VW Repair wires are the best thing to use

alexperkins wrote:They are silicon coated gold plated wires. Not the easiest to solder.

VW Repair wires are the best thing to use

I pulled my harness up through bay and soldered it there, cleaned wires up then re-soldered but took about an hour to repair two wires that someone had fitted male and female spade connectors too, saying that there must of worked until one came off.

alexperkins wrote:They are silicon coated gold plated wires. Not the easiest to solder.

VW Repair wires are the best thing to use

VW Repair wires? Please do tell - I need to sort out the MRS car and I dont feel like hacking it - anything 'kit' based or similar will be worth while.

Thanks

Vw repair wires are pre terminated replacement wires that you just use to replace what pins are damaged then you hear shrink crimp the other end of the wire

Any vw dealer can supply them, though if you can get the part number of the connector, I can give you the part numbers you'll need

alexperkins wrote:Vw repair wires are pre terminated replacement wires that you just use to replace what pins are damaged then you hear shrink crimp the other end of the wire

Any vw dealer can supply them, though if you can get the part number of the connector, I can give you the part numbers you'll need

I dont know the part number (2001 6N2) car - Ill try and look tomorrow if the rain is not too bad.

Is this basically the wires and the 'pins' that go into the plastic holder?

Thanks